Terminal device for controlling uplink signal transmission power, and method therefor

ABSTRACT

Embodiments of the present invention relate to a method and terminal device for controlling uplink transmission power. According to one embodiment, in which a terminal that communicates with cells of each timing alignment (TA) group controls uplink transmission power in the event a plurality of TA groups including one or more cells exists in a wireless communication system, a method includes: determining the uplink transmission power for at least one channel in the event at least two channels from among a physical uplink control channel (PUCCH), a physical uplink shared channel (PUSCH) including a plurality of pieces of uplink control information (UCI), a PUSCH including no UCI, a physical random access channel (PRACH), and a sounding reference signal (SRS) are simultaneously transmitted in the same subframe in each specific cell of the plurality of TA groups. The uplink transmission power is determined in consideration of a TA group index.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is the National Stage filing under 35 U.S.C. 371 ofInternational Application No. PCT/KR2012/007584, filed on Sep. 21, 2012,which claims the benefit of U.S. Provisional Application Ser. Nos.61/540,522, filed on Sep. 28, 2011, and 61/537,066, filed on Sep. 21,2011, the contents of which are all hereby incorporated by referenceherein in their entirety.

TECHNICAL FIELD

Embodiments of the present invention relate to a wireless communicationsystem supporting carrier aggregation (CA) (or multiple cells), and moreparticularly to a method and apparatus for controlling transmit (Tx)power in a wireless communication system.

BACKGROUND ART

The most important requirement of a next-generation wireless accesssystem is to support a high data transfer rate. To achieve this, varioustechnologies such as Multiple Input Multiple Output (MIMO), CooperativeMultiple Point Transmission (CoMP), relay, etc. have been developed andstudied.

Although downlink and uplink bandwidths are different, a conventionalwireless communication system typically uses one carrier. For example, awireless communication system having one carrier for each of downlinkand uplink and symmetry between downlink and uplink bandwidths may beprovided based on a single carrier.

However, in order to guarantee a broadband bandwidth capable ofsatisfying a higher data transfer rate considering that frequencyresources are saturated, carrier aggregation (CA)/multiple cellstechnology has been proposed, which is designed for each bandwidth tosatisfy basic requirements capable of operating an independent systemand aggregates a plurality of bandwidths using a single system.

In this case, a bandwidth-based carrier capable of being independentlyoperated may be referred to as a component carrier (CC). In order tosupport increased transmission capacity, a bandwidth of the latest 3GPPLTE-A or 802.16m has been continuously extended up to 20 MHz or more. Inthis case, one or more component carriers (CCs) are aggregated tosupport a broadband. For example, provided that one CC supports abandwidth of 5 MHz, 10 MHz or 20 MHz, a maximum of 5 CCs are aggregatedto support a system bandwidth of up to 100 MHz.

DISCLOSURE Technical Problem

An object of the present invention is to provide a method and apparatusfor supporting uplink power control to be considered in a carrieraggregation (CA) situation including multiple timing adjustments (TAs).

Another object of the present invention is to provide a mobile station(MS) for controlling a transmit (Tx) power.

Technical Solution

In order to solve the above-mentioned technical subject matters of thepresent invention, a method for allowing a mobile station (MS) tocontrol transmit (Tx) power in a wireless communication system includesconsidering a TA group.

The object of the present invention can be achieved by providing amethod for controlling uplink (UL) transmit (Tx) power of a mobilestation (MS) communicating with cells of each of a plurality of timingalignment (TA) groups when the plural TA groups each including one ormore cells are present in a wireless communication system includes: ifat least two channels from among a physical uplink control channel(PUCCH), a physical uplink shared channel (PUSCH) including pluraluplink control information (UCI), a PUSCH including no UCI, a physicalrandom access channel (PRACH), and a sounding reference signal (SRS) aresimultaneously transmitted in the same subframe, determining uplinktransmit (Tx) power of the at least one channel; and transmitting the atleast one channel with the determined uplink transmit (UL Tx) power,wherein the uplink transmit (UL Tx) power is determined in considerationof a timing alignment (TA) group index.

If the PRACH, the PUCCH, the PUSCH, and the SRS are contained indifferent TA groups and transmitted in different secondary cells(SCells), the PRACH may have the highest transmission (Tx) priority.

If a cell for PUCCH and PUSCH transmission and a cell for PUSCHtransmission are contained in a first TA group (TA group 1) and a cellfor PRACH transmission is contained in a second TA group (TA group 2),PRACH transmission (Tx) power of the cell contained in the second TAgroup (TA group 2) may be controlled by the following equation A:

$\begin{matrix}{{P_{PRACH}(i)} = {\min\begin{Bmatrix}{{P_{{CMAX},c}(i)},} \\{{{PREAMBLE\_ RECEIVED}{\_ TARGET}{\_ POWER}} +} \\{{PL}_{c} + {\Delta\; P_{{Ramp}\text{-}{Up\_ for}\mspace{14mu}{reference\_ TA}{\_ group}}}}\end{Bmatrix}{\quad\lbrack{dBm}\rbrack}}} & \left\lbrack {{Equation}\mspace{14mu} A} \right\rbrack\end{matrix}$

where, c is a specific cell index, i is a subframe index, P_(CMAX,c)(i)is maximum transmit (Tx) power capable of being transmitted by a mobilestation (MS), PREAMBLE_RECEIVED_TARGET_POWER is reception (Rx) power ofa RACH preamble, PL_(c) is a downlink (DL) pathloss estimation value ofa mobile station (MS) of a specific cell index (c), ΔP_(Ramp-Up) _(_)_(for reference) _(_) _(TA) _(_) _(group) is total ramp-up power rangingfrom a first preamble used in a reference TA group to the last preamble.

PREAMBLE_RECEIVED_TARGET_POWER_(TA) _(_) _(group) _(_) _(index) for eachTA group may be applied to the PREAMBLE_RECEIVED_TARGET_POWER shown inthe Equation A.

PREAMBLE_RECEIVED_TARGET_POWER_(TA) _(_) _(group) _(_) _(index) may besignaled by at least one of a higher layer, a TA-group-specific value,and a UE-specific value.

If a cell for PUCCH and PUSCH transmission and a cell for PUSCHtransmission are contained in a first TA group (TA group 1) and a cellfor PRACH transmission is contained in a second TA group (TA group 2),PUCCH transmission (Tx) power of the cell contained in the first TAgroup (TA group 1) may be controlled by the following equation B:

$\begin{matrix}{{P_{PUCCH}(i)} = {\min{\begin{Bmatrix}{{10{\log_{10}\left( {{{\hat{P}}_{{CMAX},c}(i)} - {{\hat{P}}_{PRACH}(i)}} \right)}},} \\{P_{0{\_ PUCCH}} + {PL}_{c} + {h\left( {n_{CQI},{n_{{HARQ},}n_{SR}}} \right)} +} \\{{\Delta_{F\_ PUCCH}(F)} + {\Delta_{T \times D}\left( F^{\prime} \right)} + {g(i)}}\end{Bmatrix}\lbrack{dBm}\rbrack}}} & \left\lbrack {{Equation}\mspace{14mu} B} \right\rbrack\end{matrix}$

where, c is a specific cell index, i is a subframe index, P_(PUCCH)(i)is PUCCH transmit (Tx) power at a subframe index (i) of the specificcell index (c), P_(CMAX,C)(i) is a maximum transmit (Tx) power capableof being transmitted by a mobile station (MS), {circumflex over(P)}_(CMAX,c)(i) is a linear value of P_(CMAX,c)(i), {circumflex over(P)}_(PRACH)(i) is a linear value of RACH transmit (Tx) powerP_(PUCCH)(i) at the subframe index (i), P_(O) _(_) _(PUSCH,c) (j) is aparameter composed of the sum of a cell-specific nominal component P_(O)_(_) _(NOMINAL) _(_) _(PUSCH,c) (j) provided from a higher layer of aspecific cell index (c) and a UE-specific component P_(O) _(_) _(UE)_(_) _(PUSCH,c)(j) provided from a higher layer, α_(c)(j) is acell-specific parameter, PL_(c) is a downlink (DL) pathloss estimationvalue calculated in units of dB by a mobile station (MS) of a specificcell index (c), h(n_(CQI), n_(HARQ), n_(SR)) is dependent upon a PUCCHformat, n_(CQI) is the number of information bits of channel qualityinformation (CQI), n_(HARQ) is the number of HARQ bits, n_(SR) is avalue indicating whether a specific subframe includes a transport block(TB) of PUSCH, Δ_(F) _(_) _(PUCCH)(F) is a relative value of PUCCHformat 1a, g(i) is a value indicating a current PUCCH power controladjustment state of a subframe (i), Δ_(T×D)(F′) is decided by a higherlayer in which each PUCCH format F′ is defined when PUCCH is transmittedthrough two antenna ports and is configured by the mobile station (MS).

If a cell for PUCCH and PUSCH transmission and a cell for PUSCHtransmission are contained in a first TA group (TA group 1) and a cellfor PRACH transmission is contained in a second TA group (TA group 2),PUSCH transmission (Tx) power of a cell which does not performsimultaneous transmission together with PUCCH contained in the first TAgroup (TA group 1) may be controlled by the following equation C:

$\begin{matrix}{{P_{{PUSCH},c}(i)} = {\min{\begin{Bmatrix}{{10{\log_{10}\left( {{{\hat{P}}_{{CMAX},c}(i)} - {{\hat{P}}_{PRACH}(i)}} \right)}},} \\{{10{\log_{10}\left( {M_{{PUSCH},c}(i)} \right)}} + {P_{{O\_ PUSCH},c}(j)} +} \\{{{\alpha_{c}(j)} \cdot {PL}_{c}} + {\Delta_{{TF},c}(i)} + {f_{c}(i)}}\end{Bmatrix}\lbrack{dBm}\rbrack}}} & \left\lbrack {{Equation}\mspace{14mu} C} \right\rbrack\end{matrix}$

where, c is a specific cell index, i is a subframe index, P_(PUCCH)(i)is PUCCH transmit (Tx) power at a subframe index (i) of the specificcell index (c), P_(CMAX,C)(i) is a maximum transmit (Tx) power capableof being transmitted by a mobile station (MS), {circumflex over(P)}_(CMAX,c)(i) is a linear value of P_(CMAX,c)(i), {circumflex over(P)}_(PRACH)(i) is a linear value of RACH transmit (Tx) powerP_(PUCCH)(i) at the subframe index (i), M_(PUSCH,c)(i) is a parameterindicating a PUSCH resource allocation bandwidth represented by thenumber of valid resource blocks in association with the subframe (i) ofthe specific cell index (c), P_(O) _(_) _(PUSCH,c) (j) is a parametercomposed of the sum of a cell-specific nominal component P_(O) _(_)_(NOMINAL) _(_) _(PUSCH,c)(j) received from a higher layer of thespecific cell index (c) and a UE-specific component P_(O) _(_) _(UE)_(_) _(PUSCH,c)(j) received from a higher layer, α_(c)(j) is acell-specific parameter, PL_(c) is a downlink (DL) pathloss estimationvalue calculated in units of dB by a mobile station (MS) of a specificcell index (c), f_(c)(i) is a value indicating a current PUSCH powercontrol adjustment state in association with the subframe index (i) ofthe specific cell index (c), and Δ_(TF,) _(c) (i) is a value associatedwith one codeword of the specific cell index (c).

If a cell for PUCCH and PUSCH transmission and a cell for PUSCHtransmission are contained in a first TA group (TA group 1) and a cellfor PRACH transmission is contained in a second TA group (TA group 2),PUSCH transmission (Tx) power of a cell performs simultaneoustransmission together with PUCCH contained in the first TA group (TAgroup 1) is controlled by the following equation D:

$\begin{matrix}{{P_{{PUSCH},c}(i)} = {\min{\begin{Bmatrix}{{10{\log_{10}\left( {{{\hat{P}}_{{CMAX},c}(i)} - {{\hat{P}}_{PRACH}(i)} - {{\hat{P}}_{PUCCH}(i)}} \right)}},} \\{{10{\log_{10}\left( {M_{{PUSCH},c}(i)} \right)}} + {P_{{O\_ PUSCH},c}(j)} +} \\{{{\alpha_{c}(j)} \cdot {PL}_{c}} + {\Delta_{{TF},c}(i)} + {f_{c}(i)}}\end{Bmatrix}\lbrack{dBm}\rbrack}}} & \left\lbrack {{Equation}\mspace{14mu} D} \right\rbrack\end{matrix}$

where, c is a specific cell index, i is a subframe index, P_(PUCCH)(i)is PUCCH transmit (Tx) power at a subframe index (i) of the specificcell index (c), P_(CMAX,C)(i) is a maximum transmit (Tx) power capableof being transmitted by a mobile station (MS), {circumflex over(P)}_(CMAX,c)(i) is a linear value of P_(CMAX,c)(i), {circumflex over(P)}_(PRACH)(i) is a linear value of RACH transmit (Tx) powerP_(PUCCH)(i) at the subframe index (i), M_(PUSCH,c)(i) is a parameterindicating a PUSCH resource allocation bandwidth represented by thenumber of valid resource blocks in association with the subframe (i) ofthe specific cell index (c), {circumflex over (P)}_(PUCCH,c)(i) is alinear value of PUCCH transmit (Tx) power, P_(O) _(_) _(PUSCH,c) (j) isa parameter composed of the sum of a cell-specific nominal componentP_(O) _(_) _(NOMINAL) _(_) _(PUSCH,c)(j) received from a higher layer ofthe specific cell index (c) and a UE-specific component P_(O) _(_) _(UE)_(_) _(PUSCH,c)(j) received from a higher layer, α_(c)(j) is acell-specific parameter, PL_(c) is a downlink (DL) pathloss estimationvalue calculated in units of dB by a mobile station (MS) of a specificcell index (c), f_(c)(i) is a value indicating a current PUSCH powercontrol adjustment state in association with the subframe index (i) ofthe specific cell index (c), and Δ_(TF,) _(c) is a value associated withone codeword of the specific cell index (c).

In accordance with another aspect of the present invention, a mobilestation (MS) for controlling uplink (UL) transmit (Tx) power of a mobilestation (MS) communicating with cells of each of a plurality of timingalignment (TA) groups when the plural TA groups each including one ormore cells are present in a wireless communication system includes: aprocessor, if at least two channels from among a physical uplink controlchannel (PUCCH), a physical uplink shared channel (PUSCH) includingplural uplink control information (UCI), a PUSCH including no UCI, aphysical random access channel (PRACH), and a sounding reference signal(SRS) are simultaneously transmitted in the same subframe, fordetermining uplink transmit (Tx) power of the at least one channel; anda transmitter for transmitting the at least one channel with thedetermined uplink transmit (UL Tx) power, wherein the uplink transmit(UL Tx) power is determined in consideration of a timing alignment (TA)group index.

If the PRACH, the PUCCH, the PUSCH, and the SRS are contained indifferent TA groups and transmitted in different secondary cells(SCells), the PRACH may have the highest transmission (Tx) priority.

If a cell for PUCCH and PUSCH transmission and a cell for PUSCHtransmission are contained in a first TA group (TA group 1) and a cellfor PRACH transmission is contained in a second TA group (TA group 2),PRACH transmission (Tx) power of the cell contained in the second TAgroup (TA group 2) may be controlled by the following equation A:

$\begin{matrix}{{P_{PRACH}(i)} = {\min\begin{Bmatrix}{{P_{{CMAX},c}(i)},} \\{{{PREAMBLE\_ RECEIVED}{\_ TARGET}{\_ POWER}} +} \\{{PL}_{c} + {\Delta\; P_{{Ramp}\text{-}{Up\_ for}\mspace{14mu}{reference\_ TA}{\_ group}}}}\end{Bmatrix}{\quad\lbrack{dBm}\rbrack}}} & \left\lbrack {{Equation}\mspace{14mu} A} \right\rbrack\end{matrix}$

where, c is a specific cell index, i is a subframe index, P_(CMAX,c)(i)is maximum transmit (Tx) power capable of being transmitted by a mobilestation (MS), PREAMBLE_RECEIVED_TARGET_POWER is reception (Rx) power ofa RACH preamble, PL_(c) is a downlink (DL) pathloss estimation value ofa mobile station (MS) of a specific cell index (c), ΔP_(Ramp-Up) _(_)_(for reference) _(_) _(TA) _(_) _(group) is total ramp-up power rangingfrom a first preamble used in a reference TA group to the last preamble.

PREAMBLE_RECEIVED_TARGET_POWER_(TA) _(_) _(group) _(_) _(index) for eachTA group may be applied to the PREAMBLE_RECEIVED_TARGET_POWER shown inthe Equation A.

PREAMBLE_RECEIVED_TARGET_POWER_(TA) _(_) _(group) _(_) _(index) may besignaled by at least one of a higher layer, a TA-group-specific value,and a UE-specific value.

If a cell for PUCCH and PUSCH transmission and a cell for PUSCHtransmission are contained in a first TA group (TA group 1) and a cellfor PRACH transmission is contained in a second TA group (TA group 2),PUCCH transmission (Tx) power of the cell contained in the first TAgroup (TA group 1) may be controlled by the following equation B:

$\begin{matrix}{{P_{PUCCH}(i)} = {\min{\begin{Bmatrix}{{10{\log_{10}\left( {{{\hat{P}}_{{CMAX},c}(i)} - {{\hat{P}}_{PRACH}(i)}} \right)}},} \\{P_{0{\_ PUCCH}} + {PL}_{c} + {h\left( {n_{CQI},{n_{{HARQ},}n_{SR}}} \right)} +} \\{{\Delta_{F\_ PUCCH}(F)} + {\Delta_{T \times D}\left( F^{\prime} \right)} + {g(i)}}\end{Bmatrix}\lbrack{dBm}\rbrack}}} & \left\lbrack {{Equation}\mspace{14mu} B} \right\rbrack\end{matrix}$

where, c is a specific cell index, i is a subframe index, P_(PUCCH)(i)is PUCCH transmit (Tx) power at a subframe index (i) of the specificcell index (c), P_(CMAX,C)(i) is a maximum transmit (Tx) power capableof being transmitted by a mobile station (MS), {circumflex over(P)}_(CMAX,c)(i) is a linear value of P_(CMAX,c)(i), {circumflex over(P)}_(PRACH)(i) is a linear value of RACH transmit (Tx) powerP_(PUCCH)(i) at the subframe index (i), P_(O) _(_) _(PUSCH,c)(j) is aparameter composed of the sum of a cell-specific nominal component P_(O)_(_) _(NOMINAL) _(_) _(PUSCH,c) (j) provided from a higher layer of aspecific cell index (c) and a UE-specific component P_(O) _(_) _(UE)_(_) _(PUSCH,c) (j) provided from a higher layer, α_(c) (j) is acell-specific parameter, PL_(c) is a downlink (DL) pathloss estimationvalue calculated in units of dB by a mobile station (MS) of a specificcell index (c), h(n_(CQI), n_(HARQ), n_(SR)) is dependent upon a PUCCHformat, N_(CQI) is the number of information bits of channel qualityinformation (CQI), n_(HARQ) is the number of HARQ bits, n_(SR) is avalue indicating whether a specific subframe includes a transport block(TB) of PUSCH, Δ_(F) _(_) _(PUCCH)(F) is a relative value of PUCCHformat 1a, g(i) is a value indicating a current PUCCH power controladjustment state of a subframe (i), Δ_(T×D)(F′) is decided by a higherlayer in which each PUCCH format F′ is defined when PUCCH is transmittedthrough two antenna ports and is configured by the mobile station (MS).

If a cell for PUCCH and PUSCH transmission and a cell for PUSCHtransmission are contained in a first TA group (TA group 1) and a cellfor PRACH transmission is contained in a second TA group (TA group 2),PUSCH transmission (Tx) power of a cell which does not performsimultaneous transmission together with PUCCH contained in the first TAgroup (TA group 1) may be controlled by the following equation C:

$\begin{matrix}{{P_{{PUSCH},c}(i)} = {\min{\begin{Bmatrix}{{10{\log_{10}\left( {{{\hat{P}}_{{CMAX},c}(i)} - {{\hat{P}}_{PRACH}(i)}} \right)}},} \\{{10{\log_{10}\left( {M_{{PUSCH},c}(i)} \right)}} + {P_{{O\_ PUSCH},c}(j)} +} \\{{{\alpha_{c}(j)} \cdot {PL}_{c}} + {\Delta_{{TF},c}(i)} + {f_{c}(i)}}\end{Bmatrix}\lbrack{dBm}\rbrack}}} & \left\lbrack {{Equation}\mspace{14mu} C} \right\rbrack\end{matrix}$

where, c is a specific cell index, i is a subframe index, P_(PUCCH)(i)is PUCCH transmit (Tx) power at a subframe index (i) of the specificcell index (c), P_(CMAX,C)(i) is a maximum transmit (Tx) power capableof being transmitted by a mobile station (MS), {circumflex over(P)}_(CMAX,c)(i) is a linear value of P_(CMAX,c)(i), {circumflex over(P)}_(PRACH)(i) is a linear value of RACH transmit (Tx) powerP_(PUCCH)(i) at the subframe index (i), M_(PUSCH,c)(i) is a parameterindicating a PUSCH resource allocation bandwidth represented by thenumber of valid resource blocks in association with the subframe (i) ofthe specific cell index (c), P_(O) _(_) _(PUSCH,c) (j) is a parametercomposed of the sum of a cell-specific nominal component P_(O) _(_)_(NOMINAL) _(_) _(PUSCH,c)(j) received from a higher layer of thespecific cell index (c) and a UE-specific component P_(O) _(_) _(UE)_(_) _(PUSCH,c)(j) received from a higher layer, α_(c)(j) is acell-specific parameter, PL_(c) is a downlink (DL) pathloss estimationvalue calculated in units of dB by a mobile station (MS) of a specificcell index (c), f_(c)(i) is a value indicating a current PUSCH powercontrol adjustment state in association with the subframe index (i) ofthe specific cell index (c), and Δ_(TF,) _(c) (i) is a value associatedwith one codeword of the specific cell index (c).

If a cell for PUCCH and PUSCH transmission and a cell for PUSCHtransmission are contained in a first TA group (TA group 1) and a cellfor PRACH transmission is contained in a second TA group (TA group 2),PUSCH transmission (Tx) power of a cell used for simultaneoustransmission together with PUCCH contained in the first TA group (TAgroup 1) may be controlled by the following equation D:

$\begin{matrix}{{P_{{PUSCH},c}(i)} = {\min{\begin{Bmatrix}{{10{\log_{10}\left( {{{\hat{P}}_{{CMAX},c}(i)} - {{\hat{P}}_{PRACH}(i)} - {{\hat{P}}_{PUCCH}(i)}} \right)}},} \\{{10{\log_{10}\left( {M_{{PUSCH},c}(i)} \right)}} + {P_{{O\_ PUSCH},c}(j)} +} \\{{{\alpha_{c}(j)} \cdot {PL}_{c}} + {\Delta_{{TF},c}(i)} + {f_{c}(i)}}\end{Bmatrix}\lbrack{dBm}\rbrack}}} & \left\lbrack {{Equation}\mspace{14mu} D} \right\rbrack\end{matrix}$

where, c is a specific cell index, i is a subframe index, P_(PUCCH)(i)is PUCCH transmit (Tx) power at a subframe index (i) of the specificcell index (c), P_(CMAX,c)(i) is a maximum transmit (Tx) power capableof being transmitted by a mobile station (MS), {circumflex over(P)}_(CMAX,c)(i) is a linear value of P_(CMAX,c)(i), {circumflex over(P)}_(PRACH)(i) is a linear value of RACH transmit (Tx) powerP_(PUCCH)(i) at the subframe index (i), M_(PUSCH,c)(i) is a parameterindicating a PUSCH resource allocation bandwidth represented by thenumber of valid resource blocks in association with the subframe (i) ofthe specific cell index (c), P_(PUCCH,c)(i) is a linear value of PUCCHtransmit (Tx) power, P_(O) _(_) _(PUSCH,c) (j) is a parameter composedof the sum of a cell-specific nominal component P_(O) _(_) _(NOMINAL)_(_) _(PUSCH,c)(j) received from a higher layer of the specific cellindex (c) and a UE-specific component P_(O) _(_) _(UE) _(_)_(PUSCH,c)(j) received from a higher layer, α_(c)(j) is a cell-specificparameter, PL_(c) is a downlink (DL) pathloss estimation valuecalculated in units of dB by a mobile station (MS) of a specific cellindex (c), f_(c)(i) is a value indicating a current PUSCH power controladjustment state in association with the subframe index (i) of thespecific cell index (c), and Δ_(TF,) _(c) (i) is a value associated withone codeword of the specific cell index (c).

Advantageous Effects

According to embodiments of the present invention, according to a methodfor controlling Tx power, assuming that uplink signals aresimultaneously transmitted to individual cells contained in a pluralityof TA groups, Tx power of a mobile station (MS) can be established.

It will be appreciated by persons skilled in the art that the effectsthat can be achieved through the present invention are not limited towhat has been particularly described hereinabove and other advantages ofthe present invention will be more clearly understood from the followingdetailed description.

DESCRIPTION OF DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the invention, illustrate embodiments of the inventionand together with the description serve to explain the principle of theinvention.

FIG. 1 is a block diagram illustrating a base station (BS) and a userequipment (UE) for use in a wireless communication system.

FIG. 2 is a diagram illustrating a structure of a radio frame used in a3GPP LTE system as an exemplary mobile communication system.

FIG. 3 is an exemplary structural diagram illustrating downlink anduplink subframes for use in a 3GPP LTE system as an exemplary mobilecommunication system according to the present invention.

FIG. 4 shows a downlink (DL) time-frequency resource grid structure foruse in a 3GPP LTE system.

FIG. 5 is a conceptual diagram illustrating a method for processing anuplink signal by a mobile station (MS).

FIG. 6A is a conceptual diagram illustrating multiple carriers of a basestation (BS).

FIG. 6B is a conceptual diagram illustrating multiple carriers of amobile station (MS).

FIG. 7A is a conceptual diagram illustrating multiple carriers of a basestation (BS).

FIG. 7B is a conceptual diagram illustrating multiple carriers of amobile station (MS).

FIG. 8A is a conceptual diagram illustrating multiple carriers of a basestation (BS).

FIG. 8B is a conceptual diagram illustrating multiple carriers of amobile station (MS).

FIG. 9 is a conceptual diagram illustrating a base station (BS) and RRHstructure.

BEST MODE

Reference will now be made in detail to the preferred embodiments of thepresent invention, examples of which are illustrated in the accompanyingdrawings. The detailed description, which will be given below withreference to the accompanying drawings, is intended to explain exemplaryembodiments of the present invention, rather than to show the onlyembodiments that can be implemented according to the present invention.The following detailed description includes specific details in order toprovide a thorough understanding of the present invention. However, itwill be apparent to those skilled in the art that the present inventionmay be practiced without such specific details. For example, thefollowing description will be given centering upon a mobilecommunication system serving as a 3GPP LTE or LTE-A system, but thepresent invention is not limited thereto and the remaining parts of thepresent invention other than unique characteristics of the 3GPP LTE orLTE-A system are applicable to other mobile communication systems.

In some cases, in order to prevent ambiguity of the concepts of thepresent invention, conventional devices or apparatuses well known tothose skilled in the art will be omitted and be denoted in the form of ablock diagram on the basis of important functions of the presentinvention. Wherever possible, the same reference numbers will be usedthroughout the drawings to refer to the same or like parts. Although theembodiments of the present invention are disclosed on the basis of 3GPPLTE, LTE-A systems for convenience of description, contents of thepresent invention can also be applied to other communication systems.

In a mobile communication system, the UE may receive information fromthe base station (BS) via a downlink, and may transmit information viaan uplink. The information that is transmitted and received to and fromthe UE includes data and a variety of control information. A variety ofphysical channels are used according to categories of transmission (Tx)and reception (Rx) information of the UE.

FIG. 1 is a block diagram illustrating a base station (BS) 105 and amobile station (MS) 110 for use in a wireless communication system 100according to the present invention.

Although FIG. 1 shows one BS 105 and one MS 110 for brief description ofthe wireless communication system 100, it should be noted that thewireless communication system 100 may further include one or more BSsand/or one or more MSs.

Referring to FIG. 1, the BS 105 may include a transmission (Tx) dataprocessor 115, a symbol modulator 120, a transmitter 125, atransmission/reception antenna 130, a processor 180, a memory 185, areceiver 190, a symbol demodulator 195, and a reception (Rx) dataprocessor 197. The MS 110 may include a Tx data processor 165, a symbolmodulator 170, a transmitter 175, a transmission/reception antenna 135,a processor 155, a memory 160, a receiver 140, a symbol demodulator 155,and a Rx data processor 150. In FIG. 1, although one antenna 130 is usedfor the BS 105 and one antenna 135 is used for the MS 110, each of theBS 105 and the MS 110 may also include a plurality of antennas asnecessary. Therefore, the BS 105 and the MS 110 according to the presentinvention support a Multiple Input Multiple Output (MIMO) system. The BS105 according to the present invention can support both a SingleUser-MIMO (SU-MIMO) scheme and a Multi User-MIMO (MU-MIMO) scheme.

In downlink, the Tx data processor 115 receives traffic data, formatsthe received traffic data, codes the formatted traffic data, andinterleaves the coded traffic data, and modulates the interleaved data(or performs symbol mapping upon the interleaved data), such that itprovides modulation symbols (i.e., data symbols). The symbol modulator120 receives and processes the data symbols and pilot symbols, such thatit provides a stream of symbols.

The symbol modulator 120 multiplexes data and pilot symbols, andtransmits the multiplexed data and pilot symbols to the transmitter 125.In this case, each transmission (Tx) symbol may be a data symbol, apilot symbol, or a value of a zero signal (null signal). In each symbolperiod, pilot symbols may be successively transmitted during each symbolperiod. The pilot symbols may be an FDM symbol, an OFDM symbol, a TimeDivision Multiplexing (TDM) symbol, or a Code Division Multiplexing(CDM) symbol.

The transmitter 125 receives a stream of symbols, converts the receivedsymbols into one or more analog signals, and additionally adjusts theone or more analog signals (e.g., amplification, filtering, andfrequency upconversion of the analog signals), such that it generates adownlink signal appropriate for data transmission through an RF channel.Subsequently, the downlink signal is transmitted to the RN through theantenna 130. The Tx antenna 130 transmits the generated DL signal to theUE.

Configuration of the MS 110 will hereinafter be described in detail. TheRx antenna 135 of the MS 110 receives a DL signal from the BS 105, andtransmits the DL signal to the receiver 140. The receiver 140 performsadjustment (e.g., filtering, amplification, and frequencydownconversion) of the received DL signal, and digitizes the adjustedsignal to obtain samples. The symbol demodulator 145 demodulates thereceived pilot symbols, and provides the demodulated result to theprocessor 155 to perform channel estimation.

The symbol demodulator 145 receives a frequency response estimationvalue for downlink from the processor 155, demodulates the received datasymbols, obtains data symbol estimation values (indicating estimationvalues of the transmitted data symbols), and provides the data symbolestimation values to the Rx data processor 150. The Rx data processor150 performs demodulation (i.e., symbol-demapping) of data symbolestimation values, deinterleaves the demodulated result, decodes thedeinterleaved result, and recovers the transmitted traffic data.

The processing of the symbol demodulator 145 and the Rx data processor150 is complementary to that of the symbol modulator 120 and the Tx dataprocessor 115 in the eNB 105.

The Tx data processor 165 of the MS 110 processes traffic data inuplink, and provides data symbols. The symbol modulator 170 receives andmultiplexes data symbols, and modulates the multiplexed data symbols,such that it can provide a stream of symbols to the transmitter 175. Thetransmitter 175 receives and processes the stream of symbols to generatean uplink (UL) signal, and the UL signal is transmitted to the BS 105through the Tx antenna 135.

The BS 105 receives the UL signal from the UE 110 through the antenna130. The receiver processes the received UL signal to obtain samples.Subsequently, the symbol demodulator 195 processes the symbols, andprovides pilot symbols and data symbol estimation values received viauplink. The Rx data processor 197 processes the data symbol estimationvalue, and recovers traffic data received from the UE 110.

Processor 155 or 180 of the MS 110 or the BS 105 commands or indicatesoperations of the MS 110 or the BS 105. For example, the processor 155or 180 of the MS 110 or the BS 105 controls, adjusts, and managesoperations of the MS 110 or the BS 105. Each processor 155 or 180 may beconnected to a memory unit 160 or 185 for storing program code and data.The memory 160 or 185 is connected to the processor 155 or 180, suchthat it can store the operating system, applications, and general files.

The processor 155 or 180 may also be referred to as a controller, amicrocontroller), a microprocessor, a microcomputer, etc. In themeantime, the processor 155 or 180 may be implemented by various means,for example, hardware, firmware, software, or a combination thereof. Ina hardware configuration, methods according to the embodiments of thepresent invention may be implemented by the processor 155 or 180, forexample, one or more application specific integrated circuits (ASICs),digital signal processors (DSPs), digital signal processing devices(DSPDs), programmable logic devices (PLDs), field programmable gatearrays (FPGAs), processors, controllers, microcontrollers,microprocessors, etc.

In a firmware or software configuration, methods according to theembodiments of the present invention may be implemented in the form ofmodules, procedures, functions, etc. which perform the above-describedfunctions or operations. Firmware or software implemented in the presentinvention may be contained in the processor 155 or 180 or the memoryunit 160 or 185, such that it can be driven by the processor 155 or 180.

Radio interface protocol layers among the MS 110, the BS 105, and awireless communication system (i.e., network) can be classified into afirst layer (L1 layer), a second layer (L2 layer) and a third layer (L3layer) on the basis of the lower three layers of the Open SystemInterconnection (OSI) reference model widely known in communicationsystems. A physical layer belonging to the first layer (L1) provides aninformation transfer service through a physical channel. A RadioResource Control (RRC) layer belonging to the third layer (L3) controlsradio resources between the UE and the network. The MS 110 and the BS105 may exchange RRC messages with each other through the wirelesscommunication network and the RRC layer.

FIG. 2 is a diagram illustrating a structure of a radio frame used in a3GPP LTE system acting as a mobile communication system.

Referring to FIG. 2, the radio frame has a length of 10 ms(327200*T_(s)) and includes 10 subframes of equal size. Each subframehas a length of 1 ms and includes two slots. Each slot has a length of0.5 ms (15360×T_(s)). In this case, T_(s) represents a sampling time,and is expressed by ‘T_(s)=1/(15 kHz*2048)=3.2552×10⁻⁸ (about 33 ns)’.The slot includes a plurality of OFDM or SC-FDMA symbols in a timedomain, and includes a plurality of resource blocks (RBs) in a frequencydomain.

In the LTE system, one resource block includes twelve (12) subcarriers *seven (or six) OFDM (Orthogonal Frequency Division Multiplexing)symbols. A Transmission Time Interval (TTI) which is a transmission unittime of data can be determined in a unit of one or more subframes. Theaforementioned structure of the radio frame is only exemplary, andvarious modifications can be made to the number of subframes containedin the radio frame or the number of slots contained in each subframe, orthe number of OFDM or SC-FDMA symbols in each slot.

FIG. 3 is an exemplary structural diagram illustrating downlink anduplink subframes for use in a 3GPP LTE system as an exemplary mobilecommunication system according to the present invention.

Referring to FIG. 3A, one downlink subframe includes two slots in a timedomain. A maximum of three OFDM symbols located in the front of thedownlink subframe are used as a control region to which control channelsare allocated, and the remaining OFDM symbols are used as a data regionto which a Physical Downlink Shared Channel (PDSCH) channel isallocated.

DL control channel for use in the 3GPP LTE system includes a PhysicalControl Format Indicator CHannel (PCFICH), a Physical Downlink ControlChannel (PDCCH), a Physical Hybrid-ARQ Indicator CHannel (PHICH), andthe like. The traffic channel includes a Physical Downlink SharedCHannel (PDSCH). PCFICH transmitted through a first OFDM symbol of thesubframe may carry information about the number of OFDM symbols (i.e.,the size of control region) used for transmission of control channelswithin the subframe. Control information transmitted through PDCCH isreferred to as downlink control information (DCI). The DCI may indicateUL resource allocation information, DL resource allocation information,UL transmission power control commands of arbitrary UE groups, etc.PHICH may carry ACK (Acknowledgement) NACK (Not-Acknowledgement) signalsabout an UL Hybrid Automatic Repeat Request (UL HARQ). That is, theACK/NACK signals about UL data transmitted from the UE are transmittedover PHICH.

A base station (BS) may transmit information about resource allocationand transmission format (UL grant) of the PDSCH, resource allocationinformation of the PUSCH, information about Voice over Internet Protocol(VoIP) activation, etc. A plurality of PDCCHs may be transmitted withinthe control region, and the UE may monitor the PDCCHs. Each PFCCHincludes an aggregate of one or more contiguous control channel elements(CCEs). The PDCCH composed of the aggregate of one or more contiguousCCEs may be transmitted through the control region after performingsubblock interleaving. CCE is a logical allocation unit for providing acoding rate based on a Radio frequency (RF) channel status to the PDCCH.CCE may correspond to a plurality of resource element groups. PDCCHformat and the number of available PDCCHs may be determined according tothe relationship between the number of CCEs and the coding rate providedby CCEs.

Control information transmitted over PDCCH is referred to as downlinkcontrol information (DCI). The following Table 1 shows DCIs in responseto DCI formats.

TABLE 1 DCI Format Description DCI format used for the scheduling ofPUSCH 0 DCI format used for the scheduling of one PDSCH codeword 1 DCIformat used for the compact scheduling of one PDSCH codeword 1A andrandom access procedure initiated by a PDCCH order DCI format used forthe compact scheduling of one PDSCH codeword 1B with precodinginformation DCI format used for very compact scheduling of one PDSCHcodeword 1C DCI format used for the compact scheduling of one PDSCHcodeword 1D with precoding and power offset information DCI format usedfor scheduling PDSCH to UEs configured in closed- 2 loop spatialmultiplexing mode DCI format used for scheduling PDSCH to UEs configuredin open- 2A loop spatial multiplexing mode DCI format used for thetransmission of TPC commands for PUCCH 3 and PUSCH with 2-bit poweradjustments DCI format used for the transmission of TPC commands forPUCCH 3A and PUSCH with single bit power adjustments

In Table 1, DCI format 0 may indicate uplink resource allocationinformation. DCI format 1 and DCI format 2 may indicate downlinkresource allocation information. DCI format 3 and DCI format 3A mayindicate uplink transmit power control (TPC) commands for arbitrary UEgroups.

DCI format 33A includes TPC commands of a plurality of UEs. In case ofDCI format 33A, the eNB is masked onto CRC. TPC-ID is an ID that isdemasked by a UE that monitors a PDCCH carrying a TPC command. TPC-IDmay be an ID used by a UE that decodes a PDCCH to decide transmission ornon-transmission of the TPC command over the PDCCH. TPC-ID may bedefined by reusing conventional IDs (i.e., C-RNTI(Radio NetworkTemporary Identifier), PI-RNTI, SC-RNTI, or RA-RNTI), or may be definedas a new ID. TPC-ID is an ID for UEs of a specific aggregate containedin a cell, such that it is different from C-RNTI acting as an ID of aspecific UE. In addition, the TPC JD is also different from IDs (e.g.,PI-RNTI, SC-RNTI and RA-RNTI) of all UEs contained in the cell. If DCIincludes a TPC command for N UEs, only N UEs need to receive the TPCcommands. If TPC commands for all UEs contained in the cell arecontained in a DCI, the TPC-ID is used as an ID for all UEs contained inthe cell.

The UE monitors an aggregate of PDCCH candidates in a search spacecontained in a subframe, such that it searches for TPC-ID. In this case,TPC-ID may be found either in a common search space or in a UE-specificsearch space. The common search space is a search space in which all UEscontained in the cell can perform the searching operation. TheUE-specific search space is a search space in which a specific UE canperform the searching operation. If the CRC error is not detected bydemasking a TPC-ID in the corresponding PDCCH candidate, a UE canreceive a TPC command on a PDCCH.

An identifier (ID, i.e., TPC-ID) for a PDCCH carrying a plurality of TPCcommands is defined. If TPC-ID is detected, the UE receives a TPCcommand on the corresponding PDCCH. The TPC command is used to adjusttransmission (Tx) power of an uplink channel. Therefore, the TPC commandcan prevent data or information from being transmitted to an eNB due towrong power control, or can also prevent interference for other UEs.

A method for allowing a BS to perform resource mapping for PDCCHtransmission in the LTE system will hereinafter be described in detail.

Generally, the BS may transmit scheduling allocation information andother control information over the PDCCH. Information about a physicalcontrol channel (PCCH) is configured in the form of one aggregate (oneaggregation) or several CCEs, such that the resultant information istransmitted as one aggregate or several CCEs. Namely, a PDCCHtransmission unit of the eNB is a CCE. One CCE includes 9 resourceelement groups (REGs). The number of RBGs unallocated to either PhysicalControl Format Indicator Channel (PCFICH) or Physical Hybrid AutomaticRepeat Request Indicator Channel (PHICH) is N_(RBG). CCEs from 0 toN_(CCE)−1 may be available to a system (where, N_(CCE)=└N_(REG)/9┘).PDCCH supports multiple formats as shown in the following Table 2. OnePDCCH composed of n contiguous CCEs begins with a CCE having ‘i mod n=0’(where ‘i’ is a CCE number). Multiple PDCCHs may be transmitted throughone subframe.

TABLE 2 PDCCH Number of Number of resource- Number of format CCEselement groups PDCCH bits 0 1 9 72 1 2 18 144 2 4 36 288 3 8 72 576

Referring to Table 2, an eNode B (eNB) may decide a PDCCH formataccording to how many regions are required for the BS to transmitcontrol information. The UE reads control information and the like inunits of a CCE, resulting in reduction of overhead.

Referring to FIG. 3(b), an uplink (UL) subframe may be divided into acontrol region and a data region in a frequency domain. The controlregion may be assigned to a Physical Uplink Control Channel (PUCCH)carrying uplink control information (UCI). The data region may beassigned to a Physical Uplink Shared Channel (PUSCH) carrying user data.In order to maintain single carrier characteristics, one UE does notsimultaneously transmit PUCCH and PUSCH. PUCCH for one UE may beassigned to a Resource Block (RB) pair in one subframe. RBs of the RBpair occupy different subcarriers in two slots. The RB pair assigned toPUCCH performs frequency hopping at a slot boundary.

FIG. 4 shows a downlink (DL) time-frequency resource grid structure foruse in a 3GPP LTE system.

Referring to FIG. 4, downlink transmission resources can be described bya resource grid including N_(RB) ^(DL)×N_(SC) ^(RB) subcarriers andN_(symb) ^(DL) OFDM symbols. Here, N_(RB) ^(DL) represents the number ofresource blocks (RBs) in a downlink, N_(SC) ^(RB) represents the numberof subcarriers constituting one RB, and N_(symb) ^(DL) represents thenumber of OFDM symbols in one downlink slot. N_(RB) ^(DL) varies with adownlink transmission bandwidth constructed in a cell, and must satisfyN_(RB) ^(min,DL)≦N_(RB) ^(DL)≦N_(RB) ^(max,DL). Here, N_(RB) ^(min,DL)is the smallest downlink bandwidth supported by the wirelesscommunication system, and N_(RB) ^(max,DL) is the largest downlinkbandwidth supported by the wireless communication system. AlthoughN_(RB) ^(min,DL) may be set to 6 (N_(RB) ^(min,DL)=6) and N_(RB)^(max,DL) may be set to 110 (N_(RB) ^(max,DL)=110), the scopes of N_(RB)^(min, UL) and N_(RB) ^(max,UL) are not limited thereto. The number ofOFDM symbols contained in one slot may be differently defined accordingto the length of a Cyclic Prefix (CP) and spacing between subcarriers.When transmitting data or information via multiple antennas, oneresource grid may be defined for each antenna port.

Each element contained in the resource grid for each antenna port iscalled a resource element (RE), and can be identified by an index pair(k,l) contained in a slot, where k is an index in a frequency domain andis set to any one of 0, . . . , N_(RB) ^(DL) N_(sc) ^(RB)−1, and l is anindex in a time domain and is set to any one of 0, . . . , N_(symb)^(DL)−1.

Resource blocks (RBs) shown in FIG. 4 are used to describe a mappingrelationship between certain physical channels and resource elements(REs). The RBs can be classified into physical resource blocks (PRBs)and virtual resource blocks (VRBs). One PRB is defined by N_(symb) ^(DL)consecutive OFDM symbols in a time domain and N_(SC) ^(RB) consecutivesubcarriers in a frequency domain. N_(symb) ^(DL) and N_(SC) ^(RB) maybe predetermined values, respectively. For example, N_(symb) ^(DL) andN_(SC) ^(RB) may be given as shown in the following Table 1. Therefore,one PRB may be composed of N_(symb) ^(DL)×N_(SC) ^(RB) resourceelements. One PRB symb SC may correspond to one slot in a time domainand may also correspond to 180 kHz in a frequency domain, but it shouldbe noted that the scope of the present invention is not limited thereto.

TABLE 3 Configuration N_(sc) ^(RB) N_(symb) ^(DL) Normal Δf = 15 kHz 127 cyclic prefix Extended Δf = 15 kHz 6 cyclic prefix Δf = 7.5 kHz 24 3

The PRBs are assigned numbers from 0 to N_(RB) ^(DL)−1 in the frequencydomain. A PRB number n_(PRB) and a resource element index (k,l) in aslot can satisfy a predetermined relationship denoted by

$n_{PRB} = {\left\lfloor \frac{k}{N_{sc}^{RB}} \right\rfloor.}$

The VRB may have the same size as that of the PRB. The VRB may beclassified into a localized VRB (LVRB) and a distributed VRB (DVRB). Foreach VRB type, a pair of PRBs allocated over two slots of one subframeis assigned a single VRB number n_(VRB).

The VRB may have the same size as that of the PRB. Two types of VRBs aredefined, the first one being a localized VRB (LVRB) and the second onebeing a distributed type (DVRB). For each VRB type, a pair of PRBs mayhave a single VRB index (which may hereinafter be referred to as a ‘VRBnumber’) and are allocated over two slots of one subframe. In otherwords, N_(RB) ^(DL) VRBs belonging to a first one of two slotsconstituting one subframe are each assigned any one index of 0 to N_(RB)^(DL)−1, and N_(RB) ^(DL) VRBs belonging to a second one of the twoslots are likewise each assigned any one index of 0 to N_(RB) ^(DL)−1.

A method for allowing the BS to transmit a PDCCH to a mobile station(MS) in the LTE system will hereinafter be described in detail.

The BS determines a PDCCH format according to a DCI to be sent to theMS, and attaches a Cyclic Redundancy Check (CRC) to control information.A unique identifier (e.g., a Radio Network Temporary Identifier (RNTI))is masked onto the CRC according to PDCCH owners or utilities. In caseof a PDCCH for a specific UE, a unique ID of a mobile station (MS), forexample, C-RNTI (Cell-RNTI) may be masked onto CRC. Alternatively, incase of a PDCCH for a paging message, a paging indication ID (forexample, R-RNTI (Paging-RNTI)) may be masked onto CRC. In case of aPDCCH for system information (SI), a system information ID (i.e.,SI-RNTI) may be masked onto CRC. In order to indicate a random accessresponse acting as a response to a MS's random access preambletransmission, RA-RNTI (Random Access—RNTI) may be masked onto CRC. Thefollowing Table 5 shows examples of IDs masked onto PDCCH.

TABLE 4 Type Identifier Description UE-specific C-RNTI used for the UEcorresponding to the C- RNTI. Common P-RNTI used for paging message.SI-RNTI used for system information (It could be differentiatedaccording to the type of system information). RA-RNTI used for randomaccess response (It could be differentiated according to subframe orPRACH slot index for UE PRACH transmission). TPC-RNTI used for uplinktransmit power control command (It could be differentiated according tothe index of UE TPC group).

If C-RNTI is used, PDCCH may carry control information for a specificUE. If another RNTI is used, PDCCH may carry common control informationthat is received by all or some UEs contained in the cell. The BSperforms channel coding of the CRC-added DCI so as to generate codeddata. The BS performs rate matching according to the number of CCEsallocated to a PDCCH format. Thereafter, the BS modulates the coded dataso as to generate modulated symbols. In addition, the BS maps themodulated symbols to physical resource elements.

FIG. 5 is a conceptual diagram illustrating a method for processing anuplink signal by a mobile station (MS).

Referring to FIG. 5, the scrambling module 501 may scramble atransmission signal in order to transmit the uplink signal. Thescrambled signal is input to the modulation mapper 502, such that themodulation mapper 502 modulates the scrambled signal to complex symbolsin Binary Phase Shift Keying (BPSK), Quadrature Phase Shift Keying(QPSK), or 16-ary Quadrature Amplitude Modulation (16QAM)/64-ary QAM(64QAM) according to the type of the transmission signal and/or achannel status. A transform precoder 503 processes the complex symbolsand a resource element mapper 504 may map the processed complex symbolsto time-frequency resource elements, for actual transmission. The mappedsignal may be transmitted to the BS through an antenna after beingprocessed in a Single Carrier-Frequency Division Multiple Access(SC-FDMA) signal generator 505.

PUCCH formats defined in 3GPP LTE Rel-8 and UE uplink transmission powerwill hereinafter be described in detail. PUCCH is a UL control channelfor carrying UL control information, and it is impossible for the LTEsystem to simultaneously transmit PUCCH and PUSCH due to single-carriercharacteristics. However, as multiple carriers (multicarrier) areintroduced into the LTE-A system, PUCCH can be transmitted along with aPUSCH at a specific component carrier [for example, a primary componentcarrier (PCell)]. PUCCH supports a plurality of formats, and a PUCCHformat supported by LTE Release 8 is shown in the following Table 5. Inthis case, PUCCH formats 2a and 2B support only a normal CP.

TABLE 5 PUCCH Modulation Number of bits per format scheme subframe,M_(bit) 1 N/A N/A 1a BPSK 1 1b QPSK 2 2 QPSK 20 2a QPSK + BPSK 21 2bQPSK + QPSK 22

In Equation 1, UL power for UL control channel transmission of a mobilestation (MS) for use in LTE Release-8 is represented in units of dBm.P _(PUCCH)(i)=min{P _(CMAX) ,P _(O) _(_) _(PUCCH) +PL+h(n _(CQI) ,N_(HARQ))+Δ_(F) _(_) _(PUCCH)(F)+g(i)}  [Equation 1]

In Equation 1, ‘i’ denotes a subframe index, and P_(CMAX) denotes amaximum power capable of being transmitted by a mobile station (MS).P_(O) _(_) _(PUCCH) is a parameter composed of the sum of cell-specificparameters, and is notified by a BS through higher layer signaling. ‘PL’is a downlink pathloss (or downlink signal-loss) estimation valuecalculated in units of dB by a mobile station (MS), and is denoted byPL=referenceSignalPower-higher layer filteredRSRP′. h(n) is dependentupon PUCCH format, n_(CQI) is the number of bits indicating channelquality information, and n_(HARQ) is the number of HARQ bits. Δ_(F) _(_)_(PUCCH)(F) is a relative value for PUCCH format 1a, corresponds toPUCCH format (F), and is notified by a BS through higher layersignaling. g(j) denotes a current PUCCH power control adjustment stateof a subframe (i.e., subframe(i)) having an index (i). In PUCCH formats1, 1a, and 1b, h(n_(CQI), n_(HARQ)) is set to zero (0). In the case of anormal cyclic prefix (CP) in PUCCH formats 2, 2a, 2b, h(n_(CQI),n_(HARQ)) can be represented by the following equation 2.

$\begin{matrix}{{h\left( {n_{CQI},n_{HARQ}} \right)} = \left\{ \begin{matrix}{10{\log_{10}\left( \frac{n_{CQI}}{4} \right)}} & {{{if}\mspace{14mu} n_{CQI}} \geq 4} \\0 & {otherwise}\end{matrix} \right.} & \left\lbrack {{Equation}\mspace{14mu} 2} \right\rbrack\end{matrix}$

Table 6 shows δ_(PUCCH) values mapped to the TPC command field in DCIformats 1A/1B/1D/1/2A/2/3, and Table 7 shows δ_(PUCCH) values mapped tothe TPC command field in DCI format 3A. In this case, δ_(PUCCH) denotesa UE-specific correction value (or power correction value).

TABLE 6 TPC Command Field in DCI format 1A/1B/1D/1/2A/2/3 δ_(PUCCH) [dB]0 −1 1 0 2 1 3 3

TABLE 7 TPC Command Field in DCI format 3A δ_(PUCCH) [dB] 0 −1 1 1

FIGS. 6A to 8B are conceptual diagrams illustrating multiple carriers ofa base station (BS) and multiple carriers of a mobile station (MS).

Environments that are taken into consideration in the embodiments of thepresent invention include all general multicarrier resourceenvironments. That is, the term “multicarrier system” or “carrieraggregation system” used in the present invention refers to a systemthat uses an aggregation of one or more carriers having a smallerbandwidth than a target bandwidth when configuring a target wideband inorder to support wideband.

When one or more carriers having a smaller bandwidth than the targetbandwidth are combined (or aggregated), bandwidths of the carriers to becombined may be limited to bandwidths that are used in the conventionalIMT system in order to maintain backward compatibility with theconventional IMT system. For example, the conventional 3GPP LTE systemsupports bandwidths of 1.4, 3, 5, 10, 15, and 20 MHz and theLTE-advanced (LTE_A) system can support a greater bandwidth than 20 MHzusing only the bandwidths supported by the LTE system. In addition, thecarrier aggregation (CA) system used in the present invention can alsodefine a new bandwidth, regardless of the bandwidths used in theconventional system, to support carrier combination (i.e., carrieraggregation).

Multiple carriers are interchangeably used with carrier aggregation andbandwidth (BW) aggregation. Here, the term “carrier aggregation” is anexpression including both contiguous carrier aggregation andnon-contiguous carrier aggregation spectrum aggregation.

In order to efficiently use multiple carriers, technology of managingseveral carriers by one MAC will be described. A transmitter is shown inFIG. 6A and a receiver is shown in FIG. 6B. At this time, in order toefficiently transmit/receive multiple carriers, both the transmitter andthe receiver must transmit/receive multiple carriers.

Briefly, one MAC manages/operates and transmits/receives one or morefrequency carriers. In addition, since frequency carriers managed by oneMAC need not be contiguous to each other, resources are more flexiblymanaged in terms of resource management. Both contiguous carrieraggregation and non-contiguous carrier aggregation can be applied to thefrequency carriers managed on MAC.

In addition to the structures of FIGS. 6A and 6B, as shown in FIGS. 7A,7B, 8A and 8B, several PHY layers may control several MAC layers but notone MAC layer.

As shown in FIGS. 7A and 7B, each carrier may be controlled by each MAClayer in one-to-one correspondence and, as shown in FIGS. 8A and 8B,each carrier may be controlled by each MAC layer in one-to-onecorrespondence with respect to some carriers and one or more carriersmay be controlled by one MAC layer with respect to the remainingcarriers.

The above system includes a plurality (1 to N) of carriers and maycontiguously or non-contiguously use carriers, regardless of an uplinkand a downlink. A TDD system is configured to manage N carriers whileincluding DL and UL transmission in carriers and a FDD system isconfigured to use a plurality of carriers in an uplink/downlink. In theexisting LTE Rel-8, although the bandwidths of the uplink and downlinkmay be differently set, transmission/reception within a single carrieris basically supported. However, in the LTE-A system, as describedabove, a plurality of carriers may be managed through carrieraggregation. In addition, in the FDD system, asymmetric carrieraggregation in which the uplink and the downlink are different in viewof the number of aggregated carriers and/or the bandwidth of the carriermay be supported.

Carrier aggregation (CA) may be comprised of component carriers(CCs)/cells (hereinafter referred to as only ‘CCs’ for convenience ofdescription) contained in an intra band, or may be comprised ofaggregations of component carriers (CCs) between inter bands. In therelated art, only one UL timing adjustment (UL TA) is establishedirrespective of CA configuration. In this case, UL TA may adjust anuplink (UL) Tx time point per MS in such a manner that Tx signals of allUEs contained in the cell can arrive at the BS at the same time pointfrom the viewpoint of BS. However, it may be difficult to establish onlyone UL TA due to a difference in frequency characteristics between interbands. In addition, assuming that multiple TA groups are supported inconsideration of the above-mentioned situation, it may be possible touse multiple primary cells (PCells), and one PCell may exist, and thePCell may be comprised of a TA group composed of SCells different fromthose of a TA group of PCell. In this case, the TA group may indicate aset of UL resources sharing the same TA value. One TA group may becomprised of only one serving cell. The relationship between theconfigured CC and the TA group must be defined by the BS. One TA groupis composed of one or more cell/component carriers (CCs). If one or morePCells are present, the UE can simultaneously transmit as many PUCCHs asthe number of PCells. In case of FDD, PCell is conceptually comprised oflinked or paired DL/UL cells/CCs (hereinafter referred to as onlycells). In this case, from the viewpoint of power control, the number ofDL cells configured to estimate a DL pathloss must be increased by thenumber of DL PCells. The UE may calculate the DL pathloss by measuring aReference Signal Received Power (RSRP) of a configured DL PCell, and mayuse the calculated DL pathloss for UL power control. The UE mustestimate RSRP/RSRQ for each configured PCell, and must report theestimated RSRP/RSRQ to the BS.

The related art has been designed on the basis of one TA and one PCell,such that associated problems may occur under the condition thatmultiple TAs are supported. In addition, in the case where PCelltransmits a preamble/sequence indicating a random access signal and atthe same time SCell transmits a PUSCH/SRS under the CA situation insteadof multiple TA situations, a power control method for solving the abovecase and a detailed method for solving associated situations are notpresent.

Therefore, assuming that multiple TA groups are formed in a system forsupporting carrier aggregation (CA), a primary cell (PCell) may bepresent per TA group, or not present per TA group. One or more cells/CCsare contained in one TA group. Another case in which multiple TA groupsare present, PCell is present only in a specific TA group, and anotherTA group is composed of only SCells may be used. In the case where arandom access signal including a preamble is transmitted per TA group soas to support TA, random access signals of individual TA groups may besimultaneously transmitted or may be transmitted at intervals of apredetermined time. If the random access signals of individual TA groupsare transmitted at intervals of a predetermined time, UL transmission(PUCCH/PUSCH/SRS) of a first TA group and a random access signaltransmitted from a second TA group can be simultaneously transmitted. Ifthe sum of simultaneously-transmitted powers of the MS exceeds a maximumTx power level, the following method may be considered.

A first method is designed to allocate Tx power by priority between Txsignals. That is, as Tx power is located closer to the leftmost side,the priority is gradually increased. The priority of UL Tx signal maycorrespond to any one of the following eleven schemes. The Tx signal maybe any one of a random access signal, a physical uplink control channel(PUCCH), a physical uplink shared channel (PUSCH) with uplink controlinformation (UCI), and PUSCH without UCI. The priorities needed forsimultaneous transmission of such Tx signals are as follows.

1. Random Access Signal>PUCCH>PUSCH with UCI>PUSCH

2. (Random Access Signal=PUCCH)>PUSCH with UCI>PUSCH

3. PUCCH>Random Access Signal>PUSCH with UCI>PUSCH

4. PUCCH>PUSCH with UCI>Random Access Signal>PUSCH

5. PUCCH>PUSCH with UCI>PUSCH>Random Access Signal

6. Random Access Signal>SRS

7. If an arbitrary TA group is activated and an additional TA groupattempts to random access, PUCCH is simultaneously transmitted to otherTA groups and no channel signals are simultaneously transmitted.

8. PUSCH for Message 3>PUCCH>PUSCH with UCI>PUSCH

9. PUSCH for Message 3=PUCCH>PUSCH with UCI>PUSCH

10. PUCCH>PUSCH for Message 3>PUSCH with UCI>PUSCH

11. PUCCH>PUSCH with UCI>PUSCH for Message 3>PUSCH

For example, according to the first scheme, assuming that Tx power isallocated according to “Random Access Signal>PUCCH>PUSCH with UCI>PUSCHwithout UCI” indicating first priority, a power control equation forPRACH, PUCCH, and PUSCH is as follows.

FIG. 9 is a conceptual diagram illustrating simultaneous transmission ofUL signals according to one embodiment.

Referring to FIG. 9, an exemplary case in which PUCCH and PUSCH aretransmitted in PCell, PUSCH is transmitted in SCell_1, and PRACH istransmitted in SCell_2 under the communication environment including TAgroup 1 including PCell and SCell_1 and a TA group 2 including TA group1 and SCell_2 will hereinafter be described in detail for convenience ofdescription.

In this case, Tx power of PRACH in SCell_2 contained in TA group 2 isrepresented by the following equation 1 or 2.

$\begin{matrix}{{P_{PRACH}(i)} = {\min{\left\{ \begin{matrix}{{P_{{CMAX},c}(i)},} \\{{{PREAMBLE\_ RECEIVED}{\_ TARGET}{\_ POWER}_{c}} + {PL}_{c}}\end{matrix} \right\}\lbrack{dBm}\rbrack}}} & \left\lbrack {{Equation}\mspace{14mu} 1} \right\rbrack \\{{P_{PRACH}(i)} = {\min\begin{Bmatrix}{{P_{{CMAX},c}(i)},} \\{{{PREAMBLE\_ RECEIVED}{\_ TARGET}{\_ POWER}} +} \\{{PL}_{c} + {\Delta\; P_{{Ramp}\text{-}{Up\_ for}\mspace{14mu}{reference\_ TA}{\_ group}}}}\end{Bmatrix}{\quad\lbrack{dBm}\rbrack}}} & \left\lbrack {{Equation}\mspace{14mu} 2} \right\rbrack\end{matrix}$

Referring to Equations 1 and 2, P_(CMAX,c) may indicate maximum powercapable of being transmitted from the MS configured in the serving cell(c), “PREAMBLE_RECEIVED_TARGET_POWER” may denote reception (Rx) power ofan RACH preamble to be used as an object of the BS. PL, may denote adownlink pathloss (or signal loss) calculated in units of dB by a mobilestation (MS) of a specific cell index (c). and is represented by“PL=referenceSignalPower−higher layer filteredRSRP”.

In Equations 1 and 2, “ PREAMBLE_RECEIVED_TARGET_POWER” may be changedto PREAMBLE_RECEIVED_TARGET_POWER_(TA) _(_) _(group) _(_) _(index) foreach TA group, and the above information is transferred to the MSthrough higher layers of individual TA groups, or isTA-group-specifically or UE-specifically transferred to the MS.Alternatively, a method for indicating a signaled value using only onevalue or a method for indicating the signaled value per serving cell maybe used as necessary.

PL_(c) may denote information regarding a reference cell for estimatingpathless per TA group, and can be commonly used by a method forinforming the MS through higher layer signaling or a method forestimating pathloss of one reference downlink (DL) cell.

In Equation 2, PRACH initial Tx power of the next TA group may be usedon the basis of successful PRACH Tx power of a reference TA group. InEquation 2, “PREAMBLE_RECEIVED_TARGET_POWER” is used by the reference TAgroup and is used to signal one value through a higher layer, the valueused in the reference TA group may be reused as PLc, and the pathlossvalue of the corresponding TA group may be used without change. There isa need to indicate information of a reference DL cell for estimatingpathloss per TA group. ΔP_(Ramp-Up) _(_) _(for reference) _(_) _(TA)_(_) _(group) is total ramp-up power ranging from a first preamble usedin the reference TA group to the last preamble.

Equation 3 may denote PUCCH Tx power of a PUCCH transmission cell fromamong serving cells of the TA group 1. In this case, the serving cellmay be a primary cell (PCell). If the serving cell indicates multiplePCells, an index must be added in the same manner as in PPUCCH,c.

                                     [Equation  3]${P_{PUCCH}(i)} = {\min{\left\{ \begin{matrix}{{10{\log_{10}\left( {{{\hat{P}}_{{CMAX},c}(i)} - {{\hat{P}}_{PRACH}(i)}} \right)}},} \\{P_{0{\_ PUCCH}} + {PL}_{c} + {h\left( {n_{CQI},n_{HARQ},n_{SR}} \right)} + {\Delta_{F\_ PUCCH}(F)} + {\Delta_{TxD}\left( F^{\prime} \right)} + {g(i)}}\end{matrix} \right\}\left\lbrack {{dB}\; m} \right\rbrack}}$

Referring to Equation 3, {circumflex over (P)}_(PRACH)(i) is a linearvalue of P_(PRACH)(i), and {circumflex over (P)}_(CMAX,c)(i) is a linearvalue of P_(CMAX,c)(i).

In Equation 3, “i” denotes a subframe index, P_(CMAX,c) denotes maximumpower capable of being transmitted from the MS of a specific cell index(c), P_(O) _(_) _(PUCCH,c) is a parameter composed of the sum ofcell-specific parameters and is indicated through higher layersignaling, and PL denotes a DL pathloss (or signal loss) calculated inunits of dB by the MS, and may be represented by“PL=referenceSignalPower-higher layer filteredRSRP”. h(n_(CQI),n_(HARQ), n_(SR)) is dependent upon a PUCCH format, where n_(CQI) is thenumber of information bits of CQI, and n_(HARQ) is the number of HARQbits in a specific subframe. If a specific subframe is composed of an SRof the MS including no transport block (TB) related to UL-SCH, n_(SR) isset to 1. If the specific subframe is not composed of the SR of the MS,n_(SR) is set to 0.

Δ_(F) _(_) _(PUCCH) (F) is a relative value of PUCCH format 1 a,corresponds to PUCCH format (F), and is indicated through higher layersignaling by the BS. g(i) is a current PUCCH power control adjustmentstate of the subframe (i). Here, n_(CQI) is the number of informationbits of CQI in a specific subframe, and n_(HARQ) is the number of HARQbits in a specific subframe. If a specific subframe is composed of an SRof the MS including no transport block (TB) related to UL-SCH, n_(SR) isset to 1. If the specific subframe is not composed of the SR of the MS,n_(SR) is set to 0. Δ_(T×D)(F′) is transmitted when PUCCH is transmittedthrough two antenna ports. If Δ_(T×D)(F′) is configured by the MS,Δ_(T×D)(F′) is determined by a higher layer in which each PUCCH formatF′ is defined.

Equation 4 represents PUSCH transmit (Tx) power of a serving cell, inwhich PUCCH and PUSCH are not simultaneously transmitted, from amongcells of TA group 1.

                                     [Equation  4]${P_{{PUSCH},c}(i)} = {\min\begin{Bmatrix}{{10{\log_{10}\left( {{{\hat{P}}_{{CMAX},c}(i)} - {{\hat{P}}_{PRAH}(i)}} \right)}},} \\{{10{\log_{10}\left( {M_{{PUSCH},c}(i)} \right)}} + {P_{{O\_ PUSCH},c}(j)} + {{\alpha_{c}(j)} \cdot {PL}_{c}} + {\Delta_{{TF},c}(i)} + {f_{c}(i)}}\end{Bmatrix}{\quad{\quad\left\lbrack {{dB}\; m} \right\rbrack}}}$

Referring to FIG. 4, P_(CMAX,c) may denote maximum power capable ofbeing transmitted by the MS of a specific cell index (c). M_(PUSCH,c)(i)is a parameter indicating a PUSCH resource allocation bandwidthrepresented by the number of valid resource blocks of the specific cellindex (c) in association with the subframe index (i), and is allocatedby the BS. P_(O) _(_) _(PUSCH,c) (j) is a parameter which is composed ofthe sum of a cell-specific nominal component P_(O) _(_) _(NOMINAL) _(_)_(PUSCH,c)(j) received from a higher layer of the specific cell index(c) and a UE-specific component P_(O) _(_) _(UE) _(_) _(PUSCH,c)(j)received from a higher layer. The BS may inform the MS of P_(O) _(_)_(PUSCH,c) (j). α_(c)(j) is provided from a higher layer of the specificcell index (c), and is a cell-specific parameter transmitted by the BSusing 3 bits. If j=0 or j=1, a is denoted by α∈{0, 0.4, 0.5, 0.6, 0.7,0.8, 0.9, 1}. If j=2, α(j) is set to 1 (where α(j)=1). α_(c)(j) isnotified from the BS to the MS. PL, may denote an estimation value of DLpathloss (or signal loss) calculated in units of dB by the MS of thespecific cell index (c), and may be denoted by“PL_(c)=referenceSignalPower−higher layer filteredRSRP”, where“referenceSignalPower” may be notified from the BS to the MS throughhigher layer signaling. f_(c)(i) may denote a current PUSCH powercontrol adjustment state of the subframe index (i) of the specific cellindex (c), and may be represented by a current absolute value oraccumulation value.

Δ_(TF,) _(c) (i) defined in 3GPP LTE/LTE-A is basically set to a valueof one codeword of the specific cell index (c). In association with aspecific codeword index, assuming that K_(S)=1.25 is established,Δ_(TF)(i)=10 log₁₀((2^(MPR·K) ^(S) −1)β_(offset) ^(PUSCH)) isestablished. Assuming that K_(S)=0 is established, Δ_(TF)(i)=0 isestablished. Ks may be a UE-specific parameter “deltaMCS-Enabled”applied to each codeword from the BS to the MS through a higher layer.Assuming that K_(S)=0 is established, Δ_(TF)(i) may be set to zero(i.e., Δ_(TF)(i)=0), such that individual codewords have the same Txpower. However, assuming that K_(S)=1.25 is established, individualcodewords may have different Tx powers according to the Tx informationsize (or the scheduled MCS level) normalized by allocation resources ofeach codeword. In this case, the parameter (MPR) may also be referred toas another parameter “Bits Per Resource Element (BPRE)” or the like.That is, assuming that Ks is not set to zero, Δ_(TF,) _(c) (i) may begenerated on the basis of the amount of information (e.g., BPRE) of aunit resource of each codeword.

In accordance with the embodiments of the present invention, Δ_(TF,)_(c) (i) may be indicated through higher layer signaling in such amanner that ° C. (U) is established per TA group, and may becell-specifically or UE-specifically indicated. In addition, referenceDL cell information may be indicated through higher layer signaling, ormay be cell-specifically or UE-specifically indicated, such that PL_(c)can be estimated by individual TA groups in different ways.Alternatively, irrespective of a TA group, the above two elements may beused as one common value as necessary.

If PUCCH (re)transmission is carried out by a random access responsegrant (if j=2), P_(O) _(_) _(UE) _(_) _(PUSCH,c)(2) and P_(O) _(_)_(NOMINAL) _(_) _(PUSCH,c)(2) of P_(O) _(_) _(PUSCH,c)(j) must besignaled per TA group, and may be indicated through higher layersignaling. Alternatively, a reference TA group is transmitted throughhigher layer signaling, and a difference value of another TA group maybe broadcast or UE-specifically indicated.

PUSCH transmission (Tx) power of the serving cell, in which PUCCH andPUSCH are simultaneously transmitted, from among cells of the TA group 1is represented by the following equation 5.

                                     [Equation  5]${P_{{PUSCH},c}(i)} = {\min\begin{Bmatrix}{{10{\log_{10}\left( {{{\hat{P}}_{{CMAX},c}(i)} - {{\hat{P}}_{PRACH}(i)} - {{\hat{P}}_{PUCCH}(i)}} \right)}},} \\{{10{\log_{10}\left( {M_{{PUSCH},c}(i)} \right)}} + {P_{{O\_ PUSCH},c}(j)} + {{\alpha_{c}(j)} \cdot {PL}_{c}} + {\Delta_{{TF},c}(i)} + {f_{c}(i)}}\end{Bmatrix}{\quad\left\lbrack {{dB}\; m} \right\rbrack}}$

Referring to Equation 5, {circumflex over (P)}_(PUCCH)(i) is a linearvalue of P_(PUCCH)(i), may be indicated through higher layer signalingin such a manner that α_(c)(j) is established per TA group, or may beTA-group-specifically or UE-specifically indicated. In addition,reference DL cell information may be indicated through higher layersignaling, or may be cell-specifically or UE-specifically indicated,such that PL_(c) can be estimated by individual TA groups in differentways. Alternatively, irrespective of a TA group, the above two elementsmay be used as one common value as necessary.

If PUCCH (re)transmission is carried out by a random access responsegrant (if j=2), P_(O) _(_) _(UE) _(_) _(PUSCH,c)(2) and P_(O) _(_)_(NOMINAL) _(_) _(PUSCH,c)(2) of P_(O) _(_) _(PUSCH,c)(j) must besignaled per TA group, and may be indicated through higher layersignaling. Alternatively, a reference TA group is transmitted throughhigher layer signaling, and a difference value of another TA group maybe broadcast or UE-specifically indicated.

If the example of Tx power configuration is generalized under a specificsituation of FIG. 9, the low-priority cases from among theabove-mentioned cases having the priorities 1 to 11 can be replaced withother cases obtained when maximum power limitation of the legacy powercontrol equation is reduced by Tx power of the former priorities locatedbefore a conventional value.

If the sum of Tx power of PRACH, Tx power of PUSCH including PUCCH andUCI, and Tx power of PUSCH including no UCI exceeds maximum Tx power({circumflex over (P)}_(CMAX)(i)) of the MS, the MS may adjust each Txpower of each serving cell using the following conditions.

Assuming that PUCCH is transmitted only in one serving cell, and PUCCHand PRACH are simultaneously transmitted, PUCCH transmit (Tx) power canbe adjusted using Equations 1 and 3.

Assuming that PUCCH is transmitted in only one serving cell, and PUCCH,PUSCH, PRACH are simultaneously transmitted, PUCCH Tx power can beadjusted to satisfy the following equation 6. Here, another caseincluding no PUCCH transmission may be used. If PUCCH transmission isnot used, {circumflex over (P)}_(PUCCH)(i)=0 may be established. Thatis, Tx power of PUSCH is obtained when linear values of PRACH and PUCCHTx powers according to priority are excluded from a linear value ofmaximum Tx power of the MS, and the scaling factor w(i) is applied tothe remaining Tx power, such that PUSCH Tx power can be adjusted.

$\begin{matrix}{{\sum\limits_{c}{{w(i)} \cdot {{\hat{P}}_{{PUSCH},c}(i)}}} \leq \left( {{{\hat{P}}_{CMAX}(i)} - {{\hat{P}}_{PRACH}(i)} - {{\hat{P}}_{PUCCH}(i)}} \right)} & \left\lbrack {{Equation}\mspace{14mu} 6} \right\rbrack\end{matrix}$

Equation 7 represents a condition of Tx power of a PUSCH including UCI,Tx power of PUSCH including no UCI, and Tx power of PUSCH which does notinclude UCI needed for simultaneous transmission of PRACH. Referring toEquation 7, maximum Tx power of the MS may consider not only a linearvalue of PRACH Tx power but also a linear value of PUSCH Tx powerincluding UCI, such that Tx power of PUSCH including no UCI can bedecided.

$\begin{matrix}{{\sum\limits_{c \neq j}{{w(i)} \cdot {{\hat{P}}_{{PUSCH},c}(i)}}} \leq \left( {{{\hat{P}}_{CMAX}(i)} - {{\hat{P}}_{PRACH}(i)} - {{\hat{P}}_{{PUSCH},j}(i)}} \right)} & \left\lbrack {{Equation}\mspace{14mu} 7} \right\rbrack\end{matrix}$

In Equations 8 and 9, PUSCH Tx power needed when the serving cell (j)simultaneously transmits a PUCCH and a PUSCH including UCI, the otherserving cell transmits a PUSCH including no UCI, and another servingcell transmits a PRACH can satisfy the following equation 8 or 9.

Referring to Equation 9, a maximum Tx power of the MS can determinePUSCH Tx power in consideration of a linear value of PRACH Tx power anda linear value of PUCCH Tx power.

Referring to Equation 9, assuming that PUSCH including UCI istransmitted in another cell, the scaling factor w(i) is applied to Txpower of PUSCH including no UCI in consideration of PUSCH Tx powerincluding UCI, such that PUSCH Tx power can be adjusted.

$\begin{matrix}{{{\hat{P}}_{{PUSCH},j}(i)} = {\min\left( {{{\hat{P}}_{{PUSCH},j}(i)},\left( {{{\hat{P}}_{CMAX}(i)} - {{\hat{P}}_{PRACH}(i)} - {{\hat{P}}_{PUCCH}(i)}} \right)} \right)}} & \left\lbrack {{Equation}\mspace{14mu} 8} \right\rbrack \\{{\sum\limits_{c \neq j}{{w(i)} \cdot {{\hat{P}}_{{PUSCH},c}(i)}}} \leq \left( {{{\hat{P}}_{CMAX}(i)} - {{\hat{P}}_{PRACH}(i)} - {{\hat{P}}_{PUCCH}(i)} - {{\hat{P}}_{{PUSCH},j}(i)}} \right)} & \left\lbrack {{Equation}\mspace{14mu} 9} \right\rbrack\end{matrix}$

Equation 10 can be satisfied when PUCCH is transmitted in one or moreserving cells.

$\begin{matrix}{{\sum\limits_{c}{{w(i)} \cdot {{\hat{P}}_{{PUCCH},c}(i)}}} \leq \left( {{{\hat{P}}_{CMAX}(i)} - {{\hat{P}}_{PRACH}(i)}} \right)} & \left\lbrack {{Equation}\mspace{14mu} 10} \right\rbrack\end{matrix}$

$\sum\limits_{c}{{\hat{P}}_{{PUCCH},c}(i)}$

Referring to Equation 10, may correspond to the sum of PUCCH Tx powersin cells to which PUCCH is allocated. That is, the sum of PUCCH Txpowers of individual cells can satisfy a specific condition in which thesum of PUCCH Tx powers does not exceed a difference in linear valuebetween maximum Tx power of the MS and the PRACH Tx power.

Equation 11 may represent a specific condition in which PUSCH Tx powerneeds to be satisfied when PUCCH, PUSCH, and PRACH are simultaneouslytransmitted.

$\begin{matrix}{{\sum\limits_{c}{{w(i)} \cdot {{\hat{P}}_{{PUSCH},c}(i)}}} \leq \left( {{{\hat{P}}_{CMAX}(i)} - {{\hat{P}}_{PRACH}(i)} - {\sum{{\hat{P}}_{PUCCH}(i)}}} \right)} & \left\lbrack {{Equation}\mspace{14mu} 11} \right\rbrack\end{matrix}$

Referring to Equation 11, Σ{circumflex over (P)}_(PUCCH)(i) is the sumof PUCCH Tx powers in cells to which PUCCH is allocated, and

$\sum\limits_{c}{{\hat{P}}_{{PUSCH},c}(i)}$is the sum of PUSCH Tx powers in cells to which PUSCH is allocated.

An exemplary case in which PUSCH including UCI, PUSCH including no UCI,and PRACH are simultaneously transmitted can satisfy the followingequation 12.

$\begin{matrix}{{\sum\limits_{c \neq j}{{w(i)} \cdot {{\hat{P}}_{{PUSCH},c}(i)}}} \leq \left( {{{\hat{P}}_{CMAX}(i)} - {{\hat{P}}_{PRACH}(i)} - {{\hat{P}}_{{PUSCH},j}(i)}} \right)} & \left\lbrack {{Equation}\mspace{14mu} 12} \right\rbrack\end{matrix}$

An exemplary case in which a PUCCH and a PUSCH including UCI aresimultaneously transmitted in the serving cell (j), a PUSCH including noUCI is transmitted in the other serving cell, and a PRACH is transmittedin another serving cell can satisfy the following equations 13 and 14.

$\begin{matrix}{{{\hat{P}}_{{PUSCH},j}(i)} = {\min\left( {{{\hat{P}}_{{PUSCH},j}(i)},\left( {{{\hat{P}}_{CMAX}(i)} - {{\hat{P}}_{PRACH}(i)} - {\sum{{\hat{P}}_{PUCCH}(i)}}} \right)} \right)}} & \left\lbrack {{Equation}\mspace{14mu} 13} \right\rbrack \\{{\sum\limits_{c \neq j}{{w(i)} \cdot {{\hat{P}}_{{PUSCH},c}(i)}}} \leq \left( {{{\hat{P}}_{CMAX}(i)} - {{\hat{P}}_{PRACH}(i)} - {\sum{{\hat{P}}_{PUCCH}(i)}} - {{\hat{P}}_{{PUSCH},j}(i)}} \right)} & \left\lbrack {{Equation}\mspace{14mu} 14} \right\rbrack\end{matrix}$

Referring to Equation 13, PUSCH Tx power including UCI may consider themaximum Tx power of the MS and a linear value of PRACH Tx power, and maybe determined in consideration of linear values of multiple PUCCH Txpowers.

Referring to Equation 14, PUSCH Tx power including UCI may consider themaximum Tx power of the MS and a linear value of PRACH Tx power, and maybe determined in consideration of linear values of multiple PUCCH Txpowers and a linear value of PUSCH Tx power including multiple UCIs.That is, each PUSCH Tx power can be adjusted using a proportionalconstant w(i) in such a manner that PUSCH Tx power including UCI cansatisfy the Equation 14.

The above priority method 2-11 can be extended in the same manner asdescribed above, and can also be used in the same manner as in Method 1according to priorities between respective signals.

If Tx power is allocated by the priority method 5, power controlequations of PRACH and SRS are shown in the following equations 15 and16.

Equation 15 or 16 may represent PRACH Tx power.

$\begin{matrix}{\mspace{79mu}{{P_{PRACH}(i)} = {\min{\begin{Bmatrix}{{P_{{CMAX},c}(i)},} \\{{{PREAMBLE\_ RECEIVED}{\_ TARGET}{\_ POWER}_{c}} + {PL}_{c}}\end{Bmatrix}\left\lbrack {{dB}\; m} \right\rbrack}}}} & \left\lbrack {{Equation}\mspace{14mu} 15} \right\rbrack \\{{P_{PRACH}(i)} = {\min\left\{ \begin{matrix}{{P_{{CMAX},c}(i)},} \\{{{PREAMBLE\_ RECEIVED}{\_ TARGET}{\_ POWER}} + {PL}_{c} + {\Delta\; P_{{Ramp}\text{-}{Up\_ for}\mspace{14mu}{reference\_ TA}{\_ group}}}}\end{matrix} \right\}{\quad\left\lbrack {{dB}\; m} \right\rbrack}}} & \left\lbrack {{Equation}\mspace{14mu} 16} \right\rbrack\end{matrix}$

In this case, “PREAMBLE_RECEIVED_TARGET_POWER_(TA) _(_) _(group) _(_)_(index)” may be transferred per TA group through higher layersignaling, may be TA-group-specifically or UE-specifically transferredto the MS, may be signaled through one value, or may be signaled to eachserving cell.

When information of a reference cell for estimating a pathloss for eachTA group is transferred to the MS through higher layer signaling, orwhen the passloss of only one reference DL cell is estimated, PL_(c) canbe commonly used.

Equation 2 may represent the exemplary case in which PRACH initial Txpower of the next TA group is used on the basis of successful PRACH Txpower of the reference TA group. In Equation 2,“PREAMBLE_RECEIVED_TARGET_POWER” may denote a specific value used in thereference TA group, and only one value of“PREAMBLE_RECEIVED_TARGET_POWER” is signaled through a higher layer. PLcmay be reused as a value used in the reference TA group, or may use thepathloss value of the corresponding TA group. Information of a referencedownlink cell for estimating the pathloss for each TA group must beindicated. ΔP_(Ramp-Up) _(_) _(for reference) _(_) _(TA) _(_) _(group)is total ramp-up power ranging from a first preamble used in thereference TA group to the last preamble.

Equation 17 may denote SRS Tx power. In this case, according topriorities of individual channels in relation to SRS Tx power, SRS Txpower can be determined in consideration of a linear value of PRACH Txpower.

                                     [Equation  17]${P_{{SRS},c}(i)} = {\min\left\{ \begin{matrix}{{10{\log_{10}\left( {{{\hat{P}}_{{CMAX},c}(i)} - {{\hat{P}}_{PRACH}(i)}} \right)}},} \\{{P_{{SRS\_ OFFSET},c}(m)} + {10{\log_{10}\left( M_{{SRS},c} \right)}} + {P_{{O\_ PUSCH},c}(j)} + {{\alpha_{c}(j)} \cdot {PL}_{c}} + {f_{c}(i)}}\end{matrix} \right\}{\quad\left\lbrack {{dB}\; m} \right\rbrack}}$

Referring to Equation 17, ‘i’ may denote a subframe index, andP_(SRS,c)(i) is SRS power transmitted in the subframe (i) of thespecific cell index (c). P_(SRS) _(_) _(OFFSET,c)(m), M_(SRS,c), andP_(O) _(_) _(PUSCH,c)(j), α_(c)(j) may be notified from the SB to the MSthrough higher layer signaling, and f_(c)(i) is dynamically notifiedfrom the BS of a specific cell index (c) to the MS through a TPC commandof a PDCCH. P_(SRS) _(_) _(OFFSET,c)(m) is a UE-specific parameter (forexample, 4 bits) indicating a power offset value for SRS transmission ofthe specific cell index (c), is semi-statically configured in a higherlayer, and is signaled from the BS to the MS. M_(SRS,c) may denote theSRS transmission bandwidth denoted by the number of resource blocks, andf_(c)(i) may denote a specific value indicating a current PUSCH powercontrol adjustment state and be represented by a current absolute valueor accumulation value. α_(c)(j) is a cell-specific parameter capable ofbeing transmitted from the BS using 3 bits in a higher layer of thespecific cell index (c). If j=0 or 1, α_(c) may be denoted by α_(c) ∈{0,0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1}. If j=2, α_(c)(j) may be denoted byα_(c)(j)=1 that is notified from the BS to the MS.

P_(CMAX,c)(i) may denote maximum transmittable power of the MS of thespecific cell index (c), and M_(SRS,c) may denote the SRS transmissionbandwidth in the subframe (i) denoted by the number of resource blocksof the specific cell index (c). P_(O) _(_) _(PUSCH,c)(j) is a parametercomposed of the sum of a cell-specific nominal component P_(O) _(_)_(NOMINAL) _(_) _(PUSCH,c)(j) provided from a higher layer of thespecific cell index (c) and a UE-specific component P_(O) _(_) _(UE)_(_) _(PUSCH,c)(j) provided from a higher layer of the specific cellindex (c), and is notified from the BS to the MS.

PL_(,c) may denote a DL pathloss (or signal loss) estimation valuecalculated in units of dB by the UE of the specific cell index (c), andmay be represented by PL_(,c)=referenceSignalPower−higher layerfilteredRSRP. The BS may discriminate between periodic SRS transmissionand aperiodic SRS transmission, and may separately inform the MS ofP_(SRS) _(_) _(OFFSET,c)(m). For example, ‘trigger type 0’ may denote‘m=0’, and the BS may inform the UE of a power offset value foraperiodic SRS transmission through higher layer signaling. In addition,‘trigger type 1’ may denote ‘m=1’, and the BS may inform the MS of apower offset value for aperioric SRS transmission through higher layersignaling.

Assuming that the sum of Tx power of PRACH and Tx power of SRSs exceedsmaximum Tx power (P_(CMAX)(i)) of the MS, the MS may adjust {circumflexover (P)}_(SRS,c)(i) of each serving cell using the following equation18. In the same manner as in Equation 17, in association with SRS Txpower, the sum of Tx powers can be determined in consideration of alinear value of PRACH Tx power according to priorities of individualchannels.

$\begin{matrix}{{\sum\limits_{c \neq k}{{w(i)} \cdot {{\hat{P}}_{{SRS},c}(i)}}} \leq \left( {{{\hat{P}}_{CMAX}(i)} - {{\hat{P}}_{PRACH}(i)}} \right)} & \left\lbrack {{Equation}\mspace{14mu} 18} \right\rbrack\end{matrix}$

In this case, {circumflex over (P)}_(SRS,c)(i) may denote a linear valueof {circumflex over (P)}_(SRS,c)(i), {circumflex over (P)}_(PRACH)(i)may denote a linear value of P_(PRACH)(i), and {circumflex over(P)}_(CMAX)(i) may denote a linear value of {circumflex over (P)}_(CMAX)defined in the subframe (i). In addition, w(i) may denote a scalingfactor of {circumflex over (P)}_(SRS,c)(i) for the serving cell (c),where w(i) is denoted by 0<w(i)≦1. In this case, w(i) may have the samevalue between serving cells.

In addition, assuming that a TPC command of the equation indicatingPUCCH/PUSCH is in the accumulation mode in a similar way to theembodiment, and a specific serving cell for each serving cell receives arandom access response message in association with reset values off_(c)(i) and g(i), the serving cell having received the correspondingmessage must reset the accumulated TPC command to the value of 0 or aspecific value. For example, the accumulated TPC command must be set toa predetermined value or a specific value signaled by the BS.

The following description discloses setting of initial values of theabove two elements f_(c)(i) and g(i).

An initial value of the element f_(c)(i) configured to decide PUSCH Txpower is established as follows. f_(c)(i) is a specific value indicatinga current PUSCH power control adjustment state of the subframe index (i)of a specific cell index (c), and may be represented by a currentabsolute value or accumulation value.

If P_(O) _(_) _(UE) _(_) _(PUSCH,c) is changed by a higher layer and theserving cell (c) is a primary cell (PCell), or if P_(O) _(_) _(UE) _(_)_(PUSCH,c) is received through a higher layer and the serving cell (c)is a secondary cell (SCell), f_(c)(0) is set to zero (i.e., f_(c)(0)=0).

If P_(O) _(_) _(UE) _(_) _(PUSCH,c) is not changed by a higher layer andthe serving cell (c) is not identical to a primary cell (PCell), and ifP_(O) _(_) _(UE) _(_) _(PUSCH,c) is not received through a higher layerand the serving cell (c) is not identical to a secondary cell (SCell),f_(c)(0) is denoted by f_(c)(0)=ΔP_(rampup)+δ_(msg2). In this case, theserving cell (c) may be configured to transmit PRACH (random accesssignal) in each TA group. δ_(msg2) may denote a TPC command receivedfrom the random access response message transmitted for the serving cellconfigured to transmit PRACH for each TA group. ΔP_(rampup) is providedfrom a higher layer, and may denote total ramp-up power ranging from thefirst preamble to the last preamble.

An initial value of the element g(i) for determining PUCCH Tx power isestablished. g(i) may denote a current PUCCH power control adjustmentstate of the subframe (i).

If P_(O) _(_) _(UE) _(_) _(PUSCH,c) is changed by a higher layer, theinitial value of the element g(i) is set to g(0)=0.

However, assuming that P_(O) _(_) _(UE) _(_) _(PUSCH,c) is not changedby a higher layer, the initial value is denoted byg(0)=ΔP_(rampup)+δ_(msg2) In this case, δ_(msg2) is a TPC commandreceived from the random access response message transmitted for theserving cell having transmitted PRACH to each TA group, and ΔP_(rampup)is total ramp-up power ranging from a first preamble to the lastpreamble after being provided from a higher layer.

Although the above-mentioned embodiment has disclosed the situationencountered in multiple TA groups, it should be noted that the abovemethod can also be applied to another situation in which the timingadvance scheme is used as in 3GPP LTE Release-10.

For example, assuming that PUSCH/SRS transmission is achieved in PCelland SCell(s) configured to transmit the random access preamble, thepower distribution problem caused by the above simultaneous transmissionand another power control problem caused by a TA group may occur, andthe proposed schemes can be applied to the embodiment. The random accesspreamble may be transmitted to guarantee UL synchronization in PCell.That is, the random access preamble may be transmitted for either UEpositioning or scheduling request. Of course, another case in which therandom access preamble is transmitted for synchronization acquisition isnot excluded from the scope of the present invention.

In addition, the random access preamble transmitted after ULsynchronization acquisition is limited to PRACH format/signalingconfigured to use one subframe (having 1 ms or less). PRACH format isclassified into various formats according to the size of cell (or theradius of cell). Since a subframe of 2 ms and a subframe of 3 ms (i.e.,3 subframes) are also present, the above subframes are appropriate fortime synchronization, but reusing of the above subframes is not greatlybeneficial to the next case after completion of such timesynchronization.

That is, a factor value of each Tx power can be adjusted on the basis ofTA group in such a manner that synchronization adjustment is possible.

In association with priority of each transmission (Tx) channel, Tx powercan be calculated by assigning priority to RACH. Therefore, if channelsare simultaneously transmitted in individual cells contained in multipleTA groups, it may be possible to establish UL Tx power of the MS.

It will be appreciated by persons skilled in the art that the objectsthat can be achieved by the present invention are not limited to whathas been particularly described hereinabove and the above and otherobjects that the present invention can achieve will be more clearlyunderstood from the foregoing detailed description taken in conjunctionwith the accompanying drawings. The exemplary embodiments describedhereinabove are combinations of elements and features of the presentinvention. The elements or features may be considered selective unlessotherwise mentioned. Each element or feature may be practiced withoutbeing combined with other elements or features. Further, the embodimentsof the present invention may be constructed by combining parts of theelements and/or features. Operation orders described in the embodimentsof the present invention may be rearranged. Some constructions orcharacteristics of any one embodiment may be included in anotherembodiment and may be replaced with corresponding constructions orcharacteristics of another embodiment. It is apparent that the presentinvention may be embodied by a combination of claims which do not havean explicitly cited relation in the appended claims or may include newclaims by amendment after application.

It will be apparent to those skilled in the art that variousmodifications and variations can be made in the present inventionwithout departing from the spirit or scope of the invention. Therefore,the above-mentioned detailed description must be considered only forillustrative purposes instead of restrictive purposes. The scope of thepresent invention must be decided by a rational analysis of the claims,and all modifications within equivalent ranges of the present inventionare within the scope of the present invention.

Industrial Applicability

As is apparent from the above description, the BS device for controllingtransmit (Tx) power and a method for the same according to theembodiments of the present invention can be applied to various mobilecommunication systems, for example, 3GPP LTE, LTE-A, IEEE 802, and thelike.

The invention claimed is:
 1. A method of controlling transmission powersfor transmission of a plurality of channels by a user equipment in awireless communication system supporting a plurality of componentcarriers, the method comprising: determining a transmission power of aphysical random access channel (PRACH) for a PRACH transmission on afirst component carrier belonging to a first timing advance group; anddetermining a transmission power of a physical uplink control channel(PUCCH) for a PUCCH transmission on a second component carrier belongingto a second timing advance group, wherein the determining the PUCCHtransmission power comprises: if the PRACH transmission on the firstcomponent carrier belonging to the first timing advance group overlapswith the PUCCH transmission on the second component carrier belonging tothe second timing advance group with respect to time, and if a total ofthe determined PRACH transmission power and the PUCCH transmission powerexceeds a maximum transmission power configured for the user equipment,adjusting only the PUCCH transmission power.
 2. The method of claim 1,further comprising: transmitting the PRACH on the first componentcarrier belonging to the first timing advance group based on thedetermined PRACH transmission power; and transmitting the PUCCH on thesecond component carrier belonging to the second timing advance groupbased on the adjusted PUCCH transmission power.
 3. The method of claim1, wherein the first component carrier corresponds to a secondarycomponent carrier.
 4. The method of claim 1, wherein the secondcomponent carrier corresponds to a second secondary carrier or a primarycomponent carrier.
 5. The method of claim 1, wherein the user equipmentis configured with a plurality of timing advance groups including thefirst timing advance group and the second timing advance group.
 6. Themethod of claim 1, wherein determining the PUCCH transmission powercomprises: maintaining the determined PRACH transmission power whileadjusting the PUCCH transmission power if the PRACH transmission on thefirst component carrier belonging to the first timing advance groupoverlaps with the PUCCH transmission on the second component carrierbelonging to the second timing advance group with respect to time, andif the total of the determined PRACH transmission power and the PUCCHtransmission power exceeds the maximum transmission power configured forthe user equipment.
 7. The method of claim 1, wherein the PRACHtransmission on the first component carrier belonging to the firsttiming advance group overlaps with the PUCCH transmission on the secondcomponent carrier belonging to the second timing advance group withrespect to time when the PRACH transmission and the PUCCH transmissionare scheduled on a same subframe.
 8. A user equipment for controllingtransmission powers for transmission of a plurality of channels in awireless communication system supporting a plurality of componentcarriers, the user equipment comprising: a transmitter; and a processoroperatively connected to the transmitter and configured to: determine atransmission power of a physical random access channel (PRACH) for aPRACH transmission on a first component carrier belonging to a firsttiming advance group; and determine a transmission power of a physicaluplink control channel (PUCCH) for a PUCCH transmission on a secondcomponent carrier belonging to a second timing advance group, whereinthe processor is further configured to determine either the PUCCHtransmission power by: if the PRACH transmission on the first componentcarrier belonging to the first timing advance group overlaps with thePUCCH transmission on the second component carrier belonging to thesecond timing advance group with respect to time and a total of thedetermined PRACH transmission power and the PUCCH transmission powerexceeds a maximum transmission power configured for the user equipment,adjusting only the PUCCH transmission power.
 9. The user equipment ofclaim 8, further comprising wherein the transmitter is configured to:transmit the PRACH on the first component carrier belonging to the firsttiming advance group based on the determined PRACH transmission power;and transmit the PUCCH on the second component carrier belonging to thesecond timing advance group based on the adjusted PUCCH transmissionpower.
 10. The user equipment of claim 8, wherein the first componentcarrier corresponds to a secondary component carrier.
 11. The userequipment of claim 8, wherein the second component carrier correspondsto a second secondary carrier or a primary component carrier.
 12. Theuser equipment of claim 8, wherein the user equipment is configured witha plurality of timing advance groups including the first timing advancegroup and the second timing advance group.
 13. The user equipment ofclaim 8, wherein the processor is further configured to determine thePUCCH transmission power by: maintaining the determined PRACHtransmission power while adjusting the PUCCH transmission power if thePRACH transmission on the first component carrier belonging to the firsttiming advance group overlaps with the PUCCH transmission on the secondcomponent carrier belonging to the second timing advance group withrespect to time and the total of the determined PRACH transmission powerand the PUCCH transmission power exceeds the maximum transmission powerconfigured for the user equipment.
 14. The user equipment of claim 8,wherein the PRACH transmission on the first component carrier belongingto the first timing advance group overlaps with the PUCCH transmissionon the second component carrier belonging to the second timing advancegroup with respect to time when the PRACH transmission and the PUCCHtransmission are scheduled on a same subframe.